I have Bone.001 Armature selected, and I want rotate it and set a keyframe.
If I try to set the keyframe by pressing I while hovering my mouse pointer over the rotation properties on the properties panel, the following entry is created in the Graph Editor, (the rotation turns yellow when the keyframe is set)
Notice that in the first one, the keyframes are enlisted under "ArmatureAction" and in the second one, the keyframes are enlisted under "ArmatureAction > Bone.001". The second one makes sense to me because I am recording the transformation of Bone.001 so the transformations should be enlisted under the name of the object.
Question is, what's the usefulness of first approach?